1. Why do astronomers believe that the debris that create many isolated meteors come from asteroids, whereas the debris that create meteor showers are related to comets? 2. To test your understanding...

1. Why do astronomers believe that the debris that create many isolated meteors come from asteroids, whereas the debris that create meteor showers are related to comets?

2. To test your understanding of comets, do Interactive Exercise 9-2 on the Web. You can print out your results, if required.